Not only are there 9/11 memorials at the three main crash sites but also all around the country.
A reporter visits the Flight 93 National Memorial in Shanksville, PA, and remembers where she was on that day.
Learn more about the National 9/11 Pentagon Memorial in Washington, D.C., including the symbolism of its design.
The Pentagon Memorial honors the 189 people killed when the plane struck the Pentagon.
This 2016 video offers a tour of the newly opened Flight 93 Memorial in Shanksville, PA.
On September 11, 2018, a new memorial was unveiled at the Flight 93 crash site in Shanksville, PA.
New York Mayor Bill De Blasio speaks at the 9/11 Memorial & Museum dedication in 2014.
This altar, built shortly after 9/11, serves as a memorial to those who were lost in the World Trade Centers.
This structure memorializes victims from Westchester; 109 strands form an unbreakable circle merging into one tower.
These objects, found at the United Airlines Flight 93 crash site, tell the story of the people aboard the flight that day.
In Shanksville, PA, the crash site has become a memorial to the 40 passengers and crew who saved others.
This time-lapse video shows the 8-year construction of the Flight 93 National Memorial in Shanksville, PA.
Inside the 9/11 Memorial and Museum, parts of the Twin Towers are put on display.
This aerial view of the 9/11 Memorial and Museum shows the original placement of the Twin Towers.
Flowers and balloons are placed at the 9/11 Memorial and Museum in New York City by many Americans.
President Barack Obama speaks at the dedication ceremony for the National September 11 Memorial & Museum in NYC.
Completed in 2011, the Flight 93 National Memorial in Shanksville, PA honors the heroic passengers of Flight 93.